On 03/09/2015 15:11, Peter Lieven wrote: >> >>>>> edec47c main-loop: fix qemu_notify_event for aio_notify optimization >>>> Part of the above AioContext series. >>> So either the whole series or none of them I guess? >> It's a separate bug, and theoretically it's there in 2.3.1 as well, but >> no one ever reproduced it (it would hang in make check) so not >> worthwhile. > > I maybe found another case where this bugfix seems to help. For various > reasons I'm still on 2.2.1 stable with some CVE fixes manually applied.
Don't be ashamed to say that! :) > I currently work on the problem that a haning NFS Server where I mount > my CDROM ISOs from takes down the whole vServer because the main loop > hangs sooner or later. > > I already put some patches on the list which help to improve the situation: > > ide/atapi: make PIO read requests async > block/io: allow AIOCB without callback > ide/atapi: partially avoid deadlock if the storage backend is dead > block/nfs: cache allocated filesize for read-only files > > However, I ended up with one case where Qemu deadlocks in bdrv_drain_one. > > Scenario: > - Windows 2012R2 with a random ISO mounted. > - Block communication to NFS via Firewall > - execute 'eject ide1-cd0' in the HMP > - restore connectivity. > > The HMP hangs forever even if the NFS connectivity itself is restored. If that patch helps, it's not a problem to include it in other stable releases. Paolo
